Metal-Organic-Framework-Derived Co₂ P Nanoparticle/Multi-Doped Porous Carbon as a Trifunctional Electrocatalyst.

Abstract

Developing efficient and low-cost replacements for precious metals as electrocatalysts active in electrochemical reactions-the oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR)-is a top priority in renewable energy technology. In this work a highly active and very stable trifunctional electrocatalyst composed of Co₂ P embedded in Co, N, and P multi-doped carbon has been synthesized using zeolitic imidazolate frameworks as precursors. The synergistic effects between Co₂ P and the multi-heteroatom-doped carbon substrates afford materials having electrocatalytic activities for HER, OER, and ORR, which are comparable-or even superior to-those of commercial RuO₂ or Pt/C catalysts. Density functional theory calculations show that Co₂ P has a higher density of states at the Fermi level than Co_n P (0 < n < 2), which promotes electron transfer and intermediates adsorption in the catalytic process. Zinc-air batteries and water splitting devices assembled using the materials as electrode electrocatalysts show good performance and outstanding stability. This work represents a breakthrough in improving the catalytic performance of non-precious metal electrocatalysts for OER, HER, and ORR, and opens new avenues for clean energy generation.